<template>
  <div>
    <router-link tag="div" to="/" class="header-abs"><span class="iconfont header-abs-back" v-show="showAbs">&#xe60f;</span></router-link>
    <div class="header-fixed" v-show="!showAbs" :style="opacityStyle">
      <router-link to="/">
        <div class="iconfont header-back">&#xe60f;</div>
      </router-link>
      景点详情
    </div>
  </div>
</template>

<script>
export default {
  name: 'DetailHeader',
  data: function () {
    return {
      showAbs: true,
      opacityStyle: {
        opacity: 0
      }
    }
  },
  methods: {
    handleScroll () {
      const top = document.documentElement.scrollTop
      if (top > 60) {
        let opacity = top / 140
        if (opacity > 1) {
          opacity = 1
        }
        this.opacityStyle = { opacity }
        this.showAbs = false
      } else {
        this.showAbs = true
      }
    }
  },
  components: {
  },
  activated () {
    window.addEventListener('scroll', this.handleScroll)
  },
  deactivated () {
    window.removeEventListener('scroll', this.handleScroll)
  }
}
</script>

<style lang="stylus" scoped>
  @import "~styles/varibles.styl"
  .header-abs
    position absolute
    left .2rem
    top .2rem
    width .8rem
    height .8rem
    line-height .8rem
    text-align  center
    border-radius .4rem
    background rgba(0, 0, 0, .8)
    .header-abs-back
      color white
      font-size .4rem
  .header-fixed
    z-index 2
    position: fixed
    top 0
    left 0
    right 0
    height: .86rem
    line-height: .86rem
    background: $bgColor
    color: #fff
    font-size: .32rem
    text-align: center
    .header-back
      width: .64rem
      text-align: center
      font-size: .4rem
      position: absolute
      left: 0
      top: 0
      color: #fff
</style>
